There are several types of protection mechanisms that prevent unauthorized duplication of digital content. Some protection mechanisms are often loosely referred to, and thought of, as a type of digital rights management (“DRM). Considerable efforts have been made to stop duplication of digital content from one electronic device to another. For example, storage devices that are used with iPod devices include a protection mechanism that prohibits musical or audio-visual content from being transferred from one iPod device to another, in order to prevent unauthorized duplication of protected digital content.
Flash memory devices are an example SSDs. SIM (“Subscriber Identity Module”) cards, megaSIM cards, and Universal Serial Bus (“USB”) flash drives (“UFDs”) are exemplary flash memory devices. SIM cards securely store service-subscriber key data that are used to identify a subscriber. SIM cards allow users to change phones by simply removing the SIM card from one phone and inserting it into another phone.
Currently, digital content that are stored in flash storage devices are protected by a security technology known as “Trusted Flash”. “Trusted Flash” (TF) is a data storage technology that enables consumers to buy multimedia content such as music, movies, and games, on flash memory cards for use in mobile phones, laptop computers, PDAs and other compatible and supported devices. A storage device that utilizes a security technology such as the Trusted Flash is referred to herein as “secured storage device” (SSD). An SSD protects its sensitive and secured data by using an encryption engine or by placing (i.e., storing) the sensitive and secured data in a hidden or secured storage area within the SSD, and by using authentication scheme.
Music producers and movie studios, and other multimedia content originators and providers, are more willing to release multimedia content on trusted products (also referred to herein as “supported devices”) because TF technology provides the security and DRM solutions that are required by them. A DRM solution involves enforcing a DRM policy on the electronic device (e.g., cell phone, iPod). A DRM policy is a set of restrictions imposed on the electronic device, which “tell” the electronic device what operations it can do with what digital content. For example, one policy rule may allow the electronic device to play a particular song only n times, for example 3 times, another policy rule may prohibit copying of digital content; another policy rule may allow replaying a digital data stream only by a specific electronic device, and so on. Consumers will be able to download protected digital content using online digital music services, for example, through their cell phone or personal computer (“PC”).
Trusted Flash enables consumers to use their purchased multimedia content in supported devices. Trusted Flash technology empowers the memory card itself to be the manager of digital rights, thus giving consumers the freedom to transfer the storage device, and its content, to other supported devices without compromising its content protection system. Trusted Flash cards can function as regular memory cards in non-secure host devices.
Storage devices, including TF memory cards and TF storage devices in general, are present in the market with a diversity of storage capabilities (e.g., 512 megabytes to 8 gigabytes). Currently, if a TF card used by a user has no storage space left for new multimedia content, or it has poor performance or obsolete form factor, s/he would have to buy a new TF card in order to record new multimedia content. In order to enable DRM and security features, the memory space of TF cards is partitioned into several portions, as shown in FIG. 1, which is described below.
FIG. 1A shows an exemplary secured storage device (SSD) 100. SSD 100 includes mass storage area 108, which may be of a NAND flash variety. SSD 100 also includes secure storage controller 140 that manages mass storage area 108 via data and control lines 106 and communicates with host device 150 via host interface 102. Secure storage controller 140 controls all of the data storage and data retrieval to/from mass storage area 108 and data transfer to/from host device 150 by controlling, for example, “read”, “write” and “erase” operations, wear leveling, and so on, and by controlling communication with host device 150.
User storage area 110 may also include protected data that can be used by a host device only if the host device gets also usage rules that indicate to the host device how to use the protected data. Failing to get these rules, the host device will not be able to use the protected data. Only a host device that authenticates itself to SSD 100 can get usage rules, as described below in connection with restricted storage area 120 and secure management storage area 130.